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WEBSITE: chem-tox-ecotox.org/ScientificReviews.. 1 July 2020

SCIENTIFIC REVIEWS

History of Vaccines and Immunization. Cornerstone of public health for 200 years that saved

millions of human lives

Athanasios Valavanidis

Department of Chemistry, National and Kapodistrian University of Athens,

University Campus Zografou, 15784 Athens, Greece E-mail : valavanidis@chem.uoa.gr

Abstract

The history of vaccines and immunization to combat infectious diseases goes back many centuries. Chinese employed smallpox inoculation as early as the 16th century. But the scientific history of the creation of the world’s first vaccine for smallpox started with the doctor Edward Jenner in England in the 1790s. It is very difficult to estimate the global contribution of vaccines in saving lives. Reasonable estimates are in the range of around 5 million lives per year, between 1980 and 2018. In the last 200 years vaccines became a cornerstone of public health and have saved millions of human lives. More than any other public health innovation with the possible exception of improvements in sanitation and clean drinking water. Vaccines proved to be the most cost-effective means of preventing several infectious diseases, chronic diseases and some virus-related human cancers (e.g. liver and cervical cancer). The launch by WHO and its partners of the Global Polio Eradication Initiative in 1988, reduced infections by 99%, and some 5 million people have escaped paralysis. Between 2000 and 2008, measles deaths dropped worldwide by over 78% and maternal and neonatal tetanus has been eliminated in 20 of the 58 high-risk countries. During the past decades 3 major infectious diseases have attracted special attention from the international public health community: HIV (Human Immunodeficiency Virus), Malaria and Tuberculosis (TB). International campaigns and vast investment efforts have been made to develop effective vaccines against each of these infections. Today, the Global Fund Partnership (GFP) has saved 32 million lives (2018), while building resilient and sustainable systems of health. The Global Alliance for Vaccines and Immunisation (GAVI) vaccinates almost half of the world’s children, and negotiates vaccines at prices that are affordable for the poorest countries. This review contains some of the most important vaccines for the most deadly and contagious diseases, global statistics on infectious diseases and the millions of lives (mainly children) lost every year. Vaccines are now the cornerstone of global health and history shows that they have saved millions from serious disabilities and premature death.

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Introduction: History of vaccines and immunization

The history of vaccines and immunization goes back to evidence

that Chinese employed smallpox inoculation as early s the 16th century.

Also, it was thought vaccinations for smallpox to be practiced long time

ago in Africa and Turkey as well before it spread to Europe and the

Americas. Thanks revolutionary medical technologies, vaccines made

enormous contribution to the health of modern society by preventing not

only infectious diseases in all ages, but also noncommunicable diseases

such as cancer and neurodegenerative disorders. 1,2

The origin of infectious disease smallpox (εσλογιά) is unknown.

Smallpox is thought to date back to the Egyptian Empire around the

3rd century BCE based on a smallpox-like rash found on three mummies.

The earliest written description of smallpox appeared in China in the

4th century CE (Common Era). Early written descriptions also appeared in

India in the 7th century and in Asia Minor in the 10thcentury. Smallpox was

a devastating disease. On average, 3 out of every 10 people who got it

died. Those who survived were usually left with scars, which were

sometimes severe. [CDC Center of Disease Control and Prevention, USA,

History of smallpox , https://www.cdc.gov/smallpox/history/history.html].

Figure 1. Infectious diseases spread among flourishing human

civilizations, particularly in urban areas where large numbers of people living in close proximity to each other and with animals, with poor sanitation and low nutritional foods. These conditions provided fertile grounds for the spread of infectious diseases.This is a famous historical painting of doctor Edward Jenner performing the first vaccination against smallpox on the young boy James Phipps around 1796.

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One of the first methods for controlling the spread of smallpox was

the use of variolation. Named after the virus that causes smallpox (variola

virus). Variolation is the process by which material from smallpox sores

(pustules) was given to people who had never had smallpox. This was

done either by scratching the material into the arm or inhaling it through

the nose. With both types of variolation, people usually went on to develop

the symptoms associated with smallpox, such as fever and a rash. The

practice of variolation, infecting people with low doses of smallpox, dates

back to 1000 BC in Asia. [Science Direct https://www.sciencedirect.com/

topics/immunology-and-microbiology/variolation ].

Figure 2. Variola virus is the causative agent of smallpox. Smallpox was

declared eradicated in 1980 by the World Health Organization (WHO), with no known cases of naturally occurring smallpox having occurred since 1977. The last outbreak of smallpox in the United States was in 1949.

The scientific basis for vaccination began in 1796 when an English

doctor named Edward Jenner observed that milkmaids who had gotten

cowpox (a viral disease of cows' udders which, when contracted by

humans through contact, resembles mild smallpox, and was the basis of

the first smallpox vaccines) did not show any symptoms of smallpox after

variolation. The first experiment to test this theory involved milkmaid Sarah

Nelmes and James Phipps, the 8 year-old son of Jenner’s gardener. Dr.

Edward Jenner took material from a cowpox sore on Nelmes’ hand and

inoculated it into Phipps’ arm. Months later, Jenner exposed Phipps a

number of times to variola virus, but Phipps never developed smallpox.

More experiments followed, and, in 1801, Jenner published his treatise

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―On the Origin of the Vaccine Inoculation,‖ in which he summarized his

discoveries and expressed hope that ―the annihilation of the smallpox, the

most dreadful scourge of the human species, must be the final result of

this practice.‖

Figure 3. Edward Jenner (1749-1823) was an English physician from

Gloucestershire who was a contributor to the development of the smallpox vaccine. The practice of vaccination was popularized by Edward Jenner who administered the world’s first vaccination as a preventive treatment for smallpox, a disease that had killed millions of people over the centuries.

Doctor Edward Jenner was the first to publish evidence that the

vaccine was effective and provided scientific advice on its production.

Louis Pasteur (1822-1895), renowned for his discoveries of the principles

of vaccination, microbial fermentation and pasteurization, furthered the

concept of immunization through his work in microbiology. Later, the

immunization was called vaccination because it was derived from a virus

affecting cows (Latin: vacca 'cow'). Smallpox was a contagious and deadly

disease, causing the deaths of 20–60% of infected adults and over 80% of

infected children. When smallpox was finally eradicated in 1979, it had

already killed an estimated 300–500 million people in the 20th century.3

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The story of Edward Jenner, a country doctor living in Berkeley

(Gloucestershire), England, who in 1796 performed the world’s first

vaccination is very interesting how vaccination was invented and

supported by experiment and scientific knowledge. Jenner took a sample

of pus from a cowpox lesion on a milkmaid’s hand and inoculated the boy,

James Phipps. Six weeks later Jenner variolated two sites on Phipps’s

arm with smallpox, yet the boy was unaffected by this as well as

subsequent exposures. Based on 12 such experiments and 16 additional

case histories he had collected since the 1770s, Jenner published at his

own expense a volume that swiftly became a classic text in the annals of

medicine: Inquiry into the Causes and Effects of the Variolae Vaccine. The

publication gave the opportunity to other scientists and medical experts to

test the validity of the experiment. Jenner in his book made the assertion

―that the cow-pox protects the human constitution from the infection of

smallpox‖, that laid the foundation for modern vaccinology. Edward

Jenner, a country doctor, in order to formulate the vaccine discovery relied

extensively on his knowledge of the local customs of farming communities

in England and the awareness that milkmaids infected with cowpox, visible

as pustules on the hand or forearm, were immune to subsequent

outbreaks of smallpox that periodically swept through the area. The results

spread all over the world and doctors all over Europe soon adopted

Jenner’s discovery and method, leading to a dramatic decline of this

terrible infectious disease. In the 19th and 20th centuries scientists followed

the model and developed new vaccines to fight infectious diseases, such

as polio (πολιομσελiτιδα), whooping cough (κοκκύτης), measles (ιλαρά),

tetanus, yellow fever, typhus (τύφος), hepatitis B, HIV, etc.4-,8

The importance of vaccines for global health

Looking at the global health history of the last 200 years,

vaccinations have probably saved as many human lives as any other

public health innovation with the possible exception of improvements in

sanitation and clean drinking water. The Expanded Programme on

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Immunization (EPI) started by WHO in 1974. Global policies for

immunization and establishment of the goal of providing universal

immunization for all children by 1990 were established. This goal was

considered an essential element of the WHO strategy to achieve health for

all by 2000, particularly in developing countries.

[WHO The Expanded Programme of Immunization (EPI), last adapted 2013 [https://www.who.int/immunization/programmes_systems/ supply_chain/benefits_of_immunization/en/].

Figure 4. The Expanded Program on Immunization (EPI) is one of the

WHO programmes, which has a goal to make vaccines available to all the children through-out the world. Vaccines saved millions of children from diseases and mortality.

The WHO through EPI remains committed to its goal of universal

access to all relevant vaccines for all at risk. The programme aims to more

targeted groups including older children, adolescents and adults and work

in synergy with other public health programmes in order to control

infectious disease and achieve better health for all populations.

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Immunization is a proven tool for controlling and even eradicating

infectious diseases. An immunization campaign carried out by the World

Health Organization (WHO) from 1967 to 1977 resulted in the eradication

of smallpox. When the programme began, the disease still threatened 60%

of the world's population and killed 25% of infected victims.

Another very ambitious goal of WHO was the eradication of

poliomyelitis, a goal which is now within reach. Since the launch by WHO

and its partners of the Global Polio Eradication Initiative in 1988, infections

have fallen by 99%, and some five million people have escaped paralysis.

Between 2000 and 2008, measles deaths dropped worldwide by over

78%, and some regions have set a target of eliminating the disease.

Maternal and neonatal tetanus has been eliminated in 20 of the 58 high-

risk countries.9

Figure 5. In May 2012 the World Health Assembly of WHO declared

poliovirus eradication to be a global public health emergency. Afghanistan, Nigeria and Pakistan are still the only 3 countries with poliomyelitis cases.

According to WHO in 2018 an estimated 6.2 million children and

adolescents under the age of 15 years died (globally), mostly from

preventable causes. Of these deaths, 5.3 million occurred in the first 5

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years. Leading causes of death are preterm birth complications,

pneumonia, birth asphyxia, congenital anomalies, diarrhoea and malaria.

Nearly half of these deaths are in newborns. 50% of these child deaths are

preventable or can be treated with simple, affordable interventions

including immunization, adequate nutrition, safe water and food. In the last

decades vaccines are available for some of the most deadly childhood

diseases, such as measles, polio, diphtheria, tetanus, pertussis,

pneumonia due to Haemophilius influenza type B and Streptococcus

pneumonia and diarrhoea due to rotavirus. Vaccines can protect all

children from infectious illness and death. [WHO, Children: reducing

mortality, 2020, https://www.who.int/news-room/fact-sheets/detail/children-

reducing-mortality].

In the last decades the proportion of the world's children who

receive their basic vaccines has increased from 15% to nearly 90%,

although considerable regional, national and local differences remain.

Vaccination has led to eradication of smallpox and the elimination of

poliomyelitis and measles from large parts of the world, saving millions of

lives. However, despite these successes, vaccination still has the potential

to make an even greater contribution to global health. Every year on a

global scale, 3 million children in poor countries still die each year from

vaccine preventable diseases. Pneumonia, meningitis and diarrhoea

account for a 25% of childhood deaths, many of which could be prevented

with currently available vaccines. Malaria and improved tuberculosis

vaccines are on the horizon and vaccination against human

immunodeficiency virus (HIV) may ultimately become possible. The scope

of diseases that can be prevented by vaccination is expanding. Hepatitis B

virus (HBV) and human papilloma virus (HPV) vaccines are already being

used successfully to prevent liver and cervical cancers, and progress is

being made on the therapeutic use of vaccines in the treatment of cancer

and in the management of non-communicable disease such as

hypertension, diabetes and addiction.9

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Infectious diseases eradicated by effective vaccines

Eradication and elimination of viral and infectious diseases are

increasingly a part of the global health agenda of the World Health

Organization (WHO) and national medical organizations. At present only

two infectious diseases, smallpox and rinderpest (also known as cattle

plague, a contagious viral disease affecting cloven- hoofed animals mainly

cattle and buffalo), have been eradicated worldwide. Eradication is

increasingly part of the international efforts of the global health community.

Each infectious disease poses a unique set of challenges and therapeutic

issues which make some campaigns of immunization difficult.

Eradication of poliomyelitis, measles and rubella

The eradication of SMALLPOX is the only successful global

eradication campaign thus far and is testament to the immeasurable public

health benefits that can be achieved through successful vaccines. At

present there is optimism that several other viral and infectious diseases

are candidates for global eradication in the near future given sufficient

resources, effort (systematic vaccinations), and international cooperation.

Figure 6. After a global eradication campaign lasting more than 20 years,

on May 8, 1980, the World Health Assembly declared smallpox eradicated (eliminated), and no cases of naturally occurring smallpox have happened since. Smallpox killed more than 300 million people in the 20th century.

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The most important infectious diseases which are most likely to be

eradicated are, poliomyelitis (or polio), measles, and rubella, all of which

satisfy the necessary preconditions for eradication. There were many

factors that uniquely favoured smallpox eradication, but major challenges

remained with eradication of other infectious diseases. [CDC, 2020,

https://www.cdc.gov/smallpox/history/history.html ].

MEASLES. Despite the availability of highly effective measles vaccines,

measles results in approximately 900,000 deaths each year, half of which

occur in Africa. The complications of measles (such as

bronchopneumonia, diarrhea, and blindness) are most severe in

malnourished young children, especially those with vitamin A deficiency.

Based on estimates by WHO, each year measles accounts for 30% of all

deaths due to vaccine-preventable diseases and 7% of deaths due to all

causes among children under five years of age. In 1995, an estimated

$1.1 billion was spent worldwide on measles treatment. [National

Foundation for Infectious Diseases, Measles, 2020, https://www.nfid.org/

infectious-diseases/measles/].

Figure7. Measles is a highly contagious respiratory disease that can result

in severe, sometimes permanent, complications including pneumonia, seizures, brain damage, and even death. The measles, mumps, rubella (MMR) vaccine is a safe way to protect all members of a family.

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POLIOMYELITIS

Wild poliovirus cases have decreased by over 99% since 1988, from an

estimated 350,000 cases per year in more than 125 endemic countries

then, to only 33 reported cases in 2018. Poliomyelitis can cause paralysis

and even death in children. The polio virus usually affects children under 5

years of age who are not fully vaccinated. It can also affect adolescents

and adults. There are two vaccines for polio: the Oral Polio Vaccine (OPV)

and the Inactivated Polio Vaccine (IPV). OPV is taken orally as drops and

can be easily administered. It does not require a trained health worker.

OPV is still the main preventive measure against polio.

[WHO,https://www.who.int/immunization/diseases/poliomyelitis/

inactivated_polio_vaccine/Key_mess_FAQs.pdf ].

The global polio eradication initiative which is driven by both public

and private partnerships, is spearheaded by WHO, Rotary International,

Centers for Disease Control and Prevention, and the United Nations

Children's Fund (UNICEF), relies on age-specific routine childhood

immunizations supplemented with mass OPV immunization. National

immunization days (NIDs) with OPV are conducted two or more times

annually for all children under the age of five years. As nationwide polio

cases decline, immunization strategies are increasingly targeted to virus

reservoir and high-risk population areas through sub-national

immunization days and house-to-house mop-up operations. Aggressive

surveillance is key to a successful immunization strategy. Endemic

transmission is continuing in border areas of Afghanistan and Pakistan,

resulting in 200,000 new cases every year [WHO,

https://www.who.int/news-room/fact-sheets/detail/poliomyelitis ].

Poliomyelitis was once a disease feared worldwide, striking

suddenly and paralysing mainly children for life. WHO is a partner in the

Global Polio Eradication Initiative (GPEI), the largest private-public

partnership for health, which has reduced polio by 99%. Polio now

survives only among the world's poorest and most marginalized

communities, where it stalks the most vulnerable children. [WHO, Polio,

https://www.who.int/features/factfiles/polio/en/ ].

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Figure 8. After successful campaigns of immunization more than 18 million people (mostly children) are able to walk today, who would otherwise have been paralysed by poliomyelitis. An estimated 1.5 million childhood deaths have been prevented, through the systematic administration of vitamin A during polio immunization activities.

In 1988 paralytic poliomyelitis was endemic in 125 countries on five

continents, with an estimated 350,000 cases annually. The last indigenous

case of polio in the Americas was in 1991 and the in the European Region

in 1998. Wild poliovirus type 2 has not been found anywhere in the world

since mid-1999. In 2000, polio still occurred in 20 countries, with less than

3,000 cases identified worldwide. Slightly more than 250 cases were

detected in India, the world's major exporter of wild polioviruses, despite

major advances in surveillance. Vaccination has eliminated polio in almost

all countries in the world, except for 3 countries in the world, Afghanistan,

Pakistan and Nigeria (endemic countries)– and it is hoped that the disease

will soon be eradicated globally. Provision of clean water, improved

hygienic practices and sanitation are important for reducing the risk of

transmission of polio in endemic countries. [European Center for Disease

Prevention & Control, https://www.ecdc.europa.eu/en/ poliomyelitis/facts].

RUBELLA Rubella (ερσθρά) is a contagious disease caused by a virus. It is also

called German measles, but it is caused by a different virus than measles.

Most people who get rubella usually have mild illness, with symptoms that

can include a low-grade fever, sore throat, and a rash that starts on the

face and spreads to the rest of the body. Rubella can cause a miscarriage

or serious birth defects in an unborn baby if a woman is infected while she

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is pregnant. Rubella can be prevented with MMR vaccine. This protects

against three diseases: measles, mumps, and rubella. Centers of

Diseases Control and Prevention (CDC) recommends children get two

doses of MMR vaccine, starting with the first dose at 12 through 15

months of age, and the second dose at 4 through 6 years of age. Teens

and adults also should also be up to date on their MMR vaccination. MMR

vaccine is very safe and effective. One dose of the MMR vaccine is about

97% effective at preventing rubella. [Centers of Disease Control and

Prevention, https://www.cdc.gov/vaccines/vpd/rubella/index.html ].

Figure 9. Rubella can be prevented with MMR vaccine. Recommended for children to get two doses of MMR vaccine, starting with the first dose at 12 through 15 months of age, and the second dose at 4 through 6 years of age. MMR vaccine is very safe and effective. One dose of the MMR vaccine is about 97% effective at preventing rubella.

MUMPS, disease caused by virus and prevented by vaccine

Mumps (παρωτίτιδα) is an infectious disease that is caused by a

virus. Mumps typically starts with fever, headache, muscle aches,

tiredness, and loss of appetite. Then, most people will have swelling of

their salivary glands and swollen jaw. Mumps can be prevented with the

MMR triple vaccine. This vaccine protects against three diseases:

measles, mumps, and rubella. Medical pediatricians recommend children

to be immunized with two doses of MMR vaccine, starting with the first

dose at 12 through 15 months of age, and the second dose at 4 through 6

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years of age. The MMR vaccine is very safe and effective. The mumps

component of the MMR vaccine is about 88% (range: 31-95%) effective

when a person gets two doses; one dose is about 78% (range: 49%−92%)

effective. Children may also get MMRV vaccine, which protects against

measles, mumps, rubella, and varicella (chickenpox, ανεμοβλογιά). This

vaccine is only licensed for use in children who are 12 months through 12

years of age. Before the vaccine, about 186,000 cases of mumps were

reported each year in the USA. Μumps cases decreased by 99% in the

USA and in other developed countries after systematic vaccinations.

[CDC, Centers for Disease Control and Prevention, Mumps vaccination,

https://www.cdc.gov/vaccines/vpd/mumps/index.html].

International campaigns for the major infectious diseases: HIV, Malaria and Tuberculosis

During the past decades 3 major infectious diseases have attracted

special attention from the international public health community: HIV

(Human Immunodeficiency Virus), Malaria and Tuberculosis (TB).

International campaigns and vast investment efforts have been

made to develop effective vaccines against each of these infections.

Today, the Global Fund Partnership (GFP) has saved 32 million lives

(2018), while building resilient and sustainable systems of health. The

Global Fund to Fight AIDS, Tuberculosis and Malaria was created in 2002

to raise, manage and invest the world’s money to respond to three of the

deadliest infectious diseases the world has ever known. The Global Fund

Partnership mobilized and invested more than USS$4 billion a year to

support AIDS, Tuberculosis and Malaria vaccination programmes run by

local experts in more than 100 countries. The money comes 93% from

donor governments and 7% from the private sector and foundations. The

mission of the GFP is to invest the world’s money to defeat these three

diseases. [https://www.theglobalfund.org/en/overview/ ].

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Figure 10. Health programmes supported by GFP have saved 32 million

lives (2018). Deaths caused by AIDS, Malaria and TB have been reduced by 40%. There are 18.9 million people on antiretroviral drugs therapy for HIV where GFP invests. The GFP distributed 130 million mosquito nets in 2018 saving millions of children lives from malaria. Also, 5.3 million people were treated with drugs for TB in countries where GFP invests.

Deaths from AIDS have been cut in half since 2005. New drugs for

TB have significantly improved treatment outcomes, even for drug-

resistant TB. The combination of mosquito nets treated with insecticide,

and improved diagnostics and treatment have radically reduced the impact

of malaria. The estimated annual number of malaria deaths was around

405,000 in 2018. Tuberculosis (TB) still kills 1.6 million people a year,

more than any other infectious disease. AIDS, a disease that only

appeared some 30 years ago, that has killed over 35 million people, and

for which the world still do not have a vaccine or cure despite major efforts

in the last decades.10,11

Human Immunodeficiency Virus (HIV) or Acquired Immunodeficiency syndrome (AIDS).

Acquired immunodeficiency syndrome (AIDS) is a chronic,

potentially life-threatening condition caused by the Human

Immunodeficiency Virus (HIV). The infectious virus damages the human

immune system, and interferes with the body's ability to fight the

organisms that cause disease. HIV is a sexually transmitted infection and

can also be spread by contact with infected blood or from mother to child

during pregnancy, childbirth, or breast-feeding. Without medication, HIV

gradually weakens the immune system to the point that an infected

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individual may develop AIDS. Approximately 1.1 million people in the US

are living with HIV today. About 15% of them are unaware they are

infected. There is currently no cure (vaccine) for HIV/AIDS, but there are

medications that can slow the progression of the disease. These drugs

have reduced AIDS deaths in many developed nations. [National

Foundation for Infectious Diseases, https://www.nfid.org/infectious-

diseases/hiv-aids/]. According to the Global Burden of Disease study,

almost one million (954,000) people died from HIV/AIDS in 2017. To put

this into context: this was just over 50% higher than the number of deaths

from malaria in 2017.

Figure 10. The number of people living with HIV: 36.7 million, newly

infected 1.8 million (2018). AIDS-related deaths: 940,000 people (2018). 20.9 million people living with HIV were accessing antiretroviral therapy. Source: UNAIDS, 2018. The World AIDS Day is 1st of December.

Despite many efforts there is no Effective Vaccine for AIDS.

Initial optimism that advances in molecular biology would lead to the rapid

development of safe and effective HIV vaccines has been dashed.

Although success has been achieved in animal models, only one of many

trials conducted in man has given any suggestion of protection. The

reason for not having a vaccine of HIV is that it has a long dormant period

before it progresses to AIDS. During this period, the virus hides itself in the

DNA of the infected person. The body can’t find and destroy all of the

hidden copies of the virus to cure itself. So, a vaccine to buy more time

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won’t work with HIV. The HIV mutates quickly, so it’s hard to create a

vaccine to work against it. [Healthline. HIV Vaccine: How close we are?

https://www.healthline.com/health/hiv-aids/vaccine-how-close-are-

we#obstacles]. Despite these obstacles, researchers continue to try to find

a vaccine for HIV two main types of vaccines: prophylactic and

therapeutic. Most vaccines are prophylactic, which means they prevent a

person from getting a disease. Therapeutic vaccines, on the other hand,

are used to increase the body’s immune response to fight the disease.

Therapeutic vaccines are also considered sufficient treatments.

Resources mobilized from all sources for HIV programmes in low

and middle-income countries increased by an additional US$ 250 million

from 2012 to reach US$ 19,100 million in 2013 and then increased again

to an estimated US$ 21,007 million in 2015. The rising trend was due

mainly to greater domestic investments, which comprised about 57% of

the total in 2014. Nevertheless, investments in HIV will need to grow to

US$ 31,900 million in 2020 and 29,300 million in 2030 if long-term control

of the epidemic is to be achieved. 12

Despite a massive investment in HIV vaccine research which has

resulted in the development of candidate vaccines inducing humoral or

cellular immune responses to several viral antigens. A major reason for

the failure of these first generation vaccines is the extraordinary ability of

the HIV to mutate its key surface proteins involved in binding to host cell

receptors. Thus, any highly effective HIV vaccine must be able to induce

an immune response that provides protection against each of these

mutant strains. The disappointing efficacy of HIV vaccines evaluated so far

has led to a return to the laboratory and renewed attempts to define in

more detail the antigenic structure and potential variability of key HIV

proteins and the immune responses that they induce.

Various conspiracy theories were connected with HIV and confused

the issue. When the Human Immunodeficiency Virus (HIV) was discovered

in the 1980s, people immediately wondered where it had come from and

how it had found its way into humans. One conjecture that arose in the

1990s put the blame for HIV on a public health measure: a polio vaccine.

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Conspiracy theories from journalists and rumours concerning the

oral polio vaccine having been intentionally contaminated with drugs to

cause sterility and ―viruses which are known to cause HIV and AIDS‖ led

to local refusals to accept the vaccine in parts of Africa. It’s likely that

these rumours are related to the original OPV/HIV accusations. Partially as

a result of these refusals, polio flared back up in parts of Africa after

vaccination had led to positive steps toward eradication.

[History of Vaccines, Debunked the polio vaccine and HIV link, https://www.historyofvaccines.org/content/articles/debunked-polio-vaccine-and-hiv-link, Cohen J. Forensic Epidemiology: Vaccine Theory of AIDS Origins Disputed at Royal Society. Science 289(5486):1850-1851, 2000. Jegede A. What Led to the Nigerian Boycott of the Polio Vaccination Campaign? PLoS Med. 4(3): e73-, 2007. ]

Malaria, the most severe public health problems worldwide

Malaria is an infectious disease caused by parasites that invade red

blood cells. The protozoan parasites are among several species of the

genus Plasmodium. This malaria parasite is transmitted by mosquitoes

(vectors) to humans through mosquito bites that, during the bite, release

parasites into the person's blood. Antimalarial drugs taken for prophylaxis

by travelers can delay the appearance of malaria symptoms by weeks or

months, long after the traveler has left the malaria-endemic area. This can

happen particularly with P. vivax and P. ovale, both of which can produce

dormant liver stage parasites; the liver stages may reactivate and cause

disease months after the infective mosquito bite.

Since the beginning of the 21st century, millions of people have

died from malaria (mostly children). In these 15 years the global death toll

has been cut in half: from 839,000 deaths in 2000 to 438,000 in 2015.

Africa is the world region that is most affected by malaria: In 2015, the

African continent held 9 out of 10 malaria victims. From 2000 to 2015,

African deaths from malaria were reduced from 764,000 to 395,000. [Our

World in Data, Malaria, 2019, https://ourworldindata.org/malaria ].

Several companies have developed long-lasting insecticide-treated

nets (LLINs) that maintain effective levels of insecticide for at least 3

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years, even after repeated washing. The WHO Pesticide Evaluation

Scheme External (WHOPES) has given either full or interim approval to

these nets. In 2008-2010, a total of 294 million nets were distributed in

sub-Saharan Africa. [Centers for Disease Control and Prevention

https://www.cdc.gov/malaria/malaria_worldwide/reduction/itn.html].

The UN Millennium Development Goals promoted a furious spate of

donations worth almost $255 billion for malaria. Between 2000 and 2009

the global malaria aid budget grew by 28.3%. In 2015 more than 400,000

malaria global deaths were recorded (compared to more than 2 million few

years ago). As the world observes World Malaria Day, World Health

Organization (WHO) figures show reasons for optimism: the fight against

malaria has been successful in the past, with 33 countries reporting fewer

than 1,000 cases of malaria in 2015, and mortality rates cut by 60%

globally since 2000. [CNN, https://edition.cnn.com/2016/04/25/

health/world-malaria-day-funding/index.html ].

Figure 11. Medical experts believe that global malaria eradication is

possible within a generation, but only with renewed focus, new tools and

sufficient financial support. Since 2000, great progress has been made

around the globe, driven largely by the progress made by the eliminating

countries. In these malaria-eliminating countries, malaria cases declined

91%, from 1.6 million cases to 150,000, while malaria deaths dropped

81% between 2000 and 2014.

The only approved vaccine for malaria as of 2015 is RTS,S, known

by the trade name Mosquirix. It requires four injections, and has a

20

relatively low efficacy. The complexity of the malaria parasite makes

development of a malaria vaccine a very difficult task. Recent progress

has been made with the completion of a Phase 3 trial of the RTS,S/AS01

candidate vaccine and review by the European Medicines Agency and

WHO. There is currently no commercially available malaria vaccine. Over

20 other vaccine constructs are currently being evaluated in clinical trials

or are in advanced preclinical development. The malaria vaccine

candidate RTS,S/AS01 is the most advanced vaccine candidate against

the most deadly form of human malaria, Plasmodium falciparum. A Phase

3 trial with 15,460 children in seven countries in sub-Saharan Africa

(Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, and the

United Republic of Tanzania) began in May 2009 and has now been

completed. After review of the study data, the European Medicines Agency

(EMA) issued a positive Scientific Opinion about the risk-benefit balance,

upon agreement with the manufacturing company about further research

plans as part of Phase 4 evaluation. [WHO, Malaria vaccines

https://www.who.int/immunization/research/development/malaria/en/ ].

Tuberculosis (TB): deadly infectious disease with 1.5 million deaths per year

Tuberculosis (TB) is an infectious disease usually caused by

Mycobacterium tuberculosis (MTB) bacteria. Tuberculosis generally affects

the lungs, but can also affect other parts of the body. On a global scale,

1.5 million people died from TB in 2018 (including 251,000 people with

HIV). Worldwide, TB is one of the top 10 causes of death and the leading

cause from a single infectious agent. In 2018, an estimated 10 million

people fell ill with tuberculosis (TB) worldwide. 5.7 million men, 3.2 million

women and 1.1 million children. An estimated 58 million lives were saved

through TB diagnosis and treatment between 2000 and 2018. Ending the

TB epidemic by 2030 is among the health targets of the Sustainable

Development Goals of the United Nations. [WHO, Turberculosis,

20.3.2020 https://www.who.int/news-room/fact-sheets/detail/tuberculosis ].

21

The tuberculosis vaccine was discovered 90 years ago. Bacille

Calmette-Guérin (BCG) is the vaccine for tuberculosis often given to

infants and small children in countries where TB is common. But BCG

does not always protect people from getting TB.

Figure 12. Rates of TB globally have been declining at a meagre rate of

1.5% per year since 2000, making rates 18% lower today than at the start of this century. Certain regions of the world have slowly eliminated the TB disease. Absolute numbers of people infected remain high in India and China. Another region has become an epicentre based on actual rates of infection found there: countries in sub-Saharan Africa, fuelled by HIV.

The BCG vaccine against tuberculosis is an attenuated strain of

Mycobacterium bovis—bacillus Calmette—Guérin (BCG), which has been

available for 90 years, but induces only limited protection.

Although millions of doses of BCG are given to newborn babies across

the developing world each year, it is an inadequate tool to control

completely tuberculosis (TB). TB is now experiencing a resurgence as a

consequence of the HIV epidemic in Africa. Many years ago TB caused

nearly two million deaths each year, predominantly in the developing

world, which was reduced to 1,5 million recently. Medical experts believe

that new and more effective anti-tuberculosis vaccines are needed

urgently.

22

Figure 13. Medical experts agree that ultimate defeat of TB lies in the

development of a new and effective vaccine. At present Bacillus Calmette-Guérin (BCG) is the only licensed tuberculosis vaccine. The first human subject trial took place in early 1920. In 1973, the WHO Expert Committee on Tuberculosis recommended that BCG be used as widely as possible; today, 90% of all children are vaccinated with BCG making it the most administered vaccine in the world.

Two main approaches to the development of improved new TB

vaccines are being explored. One involves genetic manipulation of the

bacterium to increase its expression of a 30 kDa secretory antigen which

is thought to play a key role in the induction of the protective immune

response induced by BCG. The second approach involves incorporation of

a bacteriolysin gene from Listeria moncytogenes into BCG. A recent

review (2018) provided an overview of the innate and adaptive immune

response during M. tuberculosis infection, and presents current

developments and challenges to novel TB vaccines. A comprehensive

understanding of vaccines in preclinical and clinical studies provides

extensive insight for the development of safer and more efficient vaccines,

and may inspire new ideas for TB prevention and treatment.13

GAVI , Global Alliance of Vaccines and Immunisation

By the late 1990s, the progress of international immunisation

programmes was stalling. Nearly 30 million children in developing

countries were not fully immunised against deadly diseases, and many

others went without any immunisation at all. At the heart of the challenge

23

was an acute market failure; powerful new vaccines were becoming

available, but developing countries simply could not afford most vaccines.

In response, the Bill and Melinda Gates Foundation and a group of

founding partners brought to life an elegant solution to encourage

manufacturers to lower vaccine prices for the poorest countries in return

for long-term, high-volume and predictable demand from those countries.

In 2000, that breakthrough idea became the Global Alliance for Vaccines

and Immunisation (GAVI) [ https://www.gavi.org/our-alliance/about].

Figure 14. GAVI currently supports vaccine programmes in all 41 countries, which have a combined population of 1.52 billion. The countries were selected based on the availability of data from Demographic and Health Surveys.

The Global Alliance for Vaccines and Immunisation (GAVI) now

vaccinates almost half of the world’s children, giving it tremendous power

to negotiate vaccines at prices that are affordable for the poorest countries

and to remove the commercial risks that previously kept manufacturers

from serving them. Because of these market shaping efforts, the cost of

fully-immunising a child with all 11 WHO-recommended childhood

vaccines now costs US$ 28 in Gavi-supported countries, compared to

about US$ 1,100 in the US. At the same time, the pool of manufacturers

producing prequalified Gavi -supported vaccines has grown from five in

2001 (with one in Africa) to 17 in 2017 (with 11 in Africa, Asia and Latin

America). Gavi shares the cost developing countries pay for vaccines,

24

which has resulted in more than 460 vaccine campaigns and dramatically

boosted immunisation against virulent diseases. For example, in 2000, 3%

of low-income countries administered the Haemophilus influenza type b

vaccine that protects against diseases like pneumonia and meningitis.

Today, Gavi has enabled all low-income countries to introduce this

vaccine. So far, 15 countries that were formerly supported by Gavi have

begun to fully self-finance their national vaccination programmes.

GAVI, the Vaccine Alliance is supported by donor governments

(Australia, Brazil, Canada, Denmark, France, Germany, India, Ireland,

Italy, Japan, the Kingdom of Saudi Arabia, Luxembourg, the Netherlands,

Norway, the People’s Republic of China, Republic of Korea, Russia, South

Africa, Spain, the State of Qatar, the Sultanate of Oman, Sweden, United

Kingdom, and United States), the European Commission, Alwaleed

Philanthropies, the OPEC Fund for International Development (OFID), the

Bill & Melinda Gates Foundation, and His Highness Sheikh Mohamed bin

Zayed Al Nahyan, as well as private and corporate partners (Absolute

Return for Kids, Anglo American plc., The Children’s Investment Fund

Foundation, China Merchants Group, Comic Relief, Deutsche Post DHL,

the ELMA Vaccines and Immunization Foundation, Girl Effect, The

International Federation of Pharmaceutical Wholesalers (IFPW), the Gulf

Youth Alliance, JP Morgan, ―la Caixa‖ Foundation, LDS Charities, Lions

Clubs International Foundation, Majid Al Futtaim, Philips, Unilever, UPS

and Vodafone). [https://www.gavi.org/news/media-room/study-vaccines-

prevent-not-just-disease-also-poverty ].

Vaccines do not just save lives, they also have a huge economic

impact on families and communities. A healthy child is more likely to go to

school and become a more productive member of society in later life, while

their families can avoid the often crippling healthcare costs that diseases

can bring. The development of effective vaccines has led to a huge

decrease in childhood deaths. Vaccines are among the two global public

health interventions that have had the greatest impact on the world's

health: clean drinking water-sanitation and immunization by vaccines.'

25

Figure 15. In addition to saving millions of lives, vaccines will help prevent some of the world’s poorest countries from slipping into poverty by 2030. Health care costs forces 100 million people into poverty every year. Vaccines and immunisation efforts will prevent 24 million people in 41 countries from failing into the poverty trap (2016-2030).

Vaccines do not just save lives, they also have a huge economic

impact on families and communities. A healthy child is more likely to go to

school and become a more productive member of society in later life, while

their families can avoid the often crippling healthcare costs that diseases

can bring.

Figure 16, Since 2007 GAVI has been funding new Health System

Strengthening (HSS) programs that encourage and enable countries to

identify infrastructure and resource weaknesses that are barriers to the

achievement of immunisation and other public health goals.

26

Pneumococcal disease can be life threatening

Pneumococcal disease is a common and often mild infection, but it

can sometimes result in serious health problems. These include a middle

ear infection, a blood infection, pneumonia, or bacterial meningitis. The

bacterium Streptococcus pneumonia (S. pneumoniae), is also known as

pneumococcus, causes pneumococcal disease. Invasive pneumococcal

disease is a life-threatening condition that is fatal in 10% of cases. Older

people and those with underlying medical conditions have a higher risk

than others of serious complications. Regular vaccinations can prevent

many types of pneumococcal disease and the potential complications that

may arise.

Figure 17. GAVI the Vaccine Alliance. Pneumonia is the most important cause of death in childhood, killing around two million children under the age of 5 each year, mostly in the developing world. GAVI supports countries to introduce vaccines and prevent half a million deaths in 2015.

The development of pneumococcal polysaccharide/protein

conjugate vaccines that are effective in young children has been a major

step forward in reducing global child mortality. There are 2 kinds of

vaccines that help prevent pneumococcal disease: a. Pneumococcal

27

conjugate vaccine or PCV13, and b. Pneumococcal polysaccharide

vaccine or PPSV23. All Children Should Get Pneumococcal Vaccines.

It is recommended for pneumococcal vaccination for all children younger

than 2 years old and all adults 65 years or older. In certain situations, other

children and adults should also get pneumococcal vaccines.

Influenza (flu), contagious respiratory illness

Influenza viruses that infect the nose, throat, and lungs cause

respiratory diseases. Ihflenza can cause mild to severe illness, and can

lead to hospitalization and even death. Every year in most developed

countries, millions of people are sickened, hundreds of thousands are

hospitalized and thousands or tens of thousands of people die from the flu.

Anyone can get the flu (even healthy people) and serious problems related

to the flu can happen at any age, but some people are a higher risk of

developing serious flu-related complications if they get sick. This includes

people 65 years and older, people of any age with certain chronic medical

conditions (such as diabetes, asthma, or heart disease), pregnant women,

and young children. The best way and most important step to prevent the

flu is by getting a flu vaccine each year. It is recommended by all medical

authorities that everyone 6 months of age and older get a flu vaccine each

year. Flu vaccination can reduce flu illnesses, doctors’ visits, and missed

work and school due to flu, as well as prevent flu-related hospitalizations.

There are 4 types of seasonal influenza viruses, types A, B, C and

D. Influenza A and B viruses circulate and cause seasonal epidemics of

disease. [WHO, Seasonal Influenza, https://www.who.int/news-room/fact-

sheets/detail/influenza-(seasonal) ].

Influenza A viruses are further classified into subtypes according to the

combinations of the hemagglutinin (HA) and the neuraminidase (NA), the

proteins on the surface of the virus. Currently circulating in humans are

subtype A(H1N1) and A(H3N2) influenza viruses.

Influenza B viruses are not classified into subtypes, but can be broken

down into lineages.

28

Influenza C virus is detected less frequently and usually causes mild

infections, thus does not present public health importance.

Influenza D viruses primarily affect cattle and are not known to infect or

cause illness in people.

The current strain of avian flu (H5N1) is not highly transmissible in

humans but has the potential to cause a very serious illness with a high

mortality rate when it does. The recent variant of swine flu (H1N1) is not

especially virulent but causes serious illness in younger subjects more

frequently than do the influenza strains that have circulated in

industrialized countries in recent years. In temperate climates, influenza

occurs as regular seasonal outbreaks interspersed with periodic large

epidemics associated with the emergence of a new strain.

The World Health Organization (WHO) estimates that worldwide,

annual influenza epidemics result in about 3-5 million cases of severe

illness and about 250,000 to 500,000 deaths. The most recent data for the

mortality (death rates) from influenza for the United States in 2016

indicates that mortality from influenza varies from year to year. Death rates

estimated by the CDC (USA) range from about 12,000 during 2011-2012

to 56,000 during 2012-2013. In the 2017-2018 season, deaths (USA)

reached a new high of about 79,000. Experts suggest that a large

percentage of people went unvaccinated or refused to vaccinate family

members. [Medscape, Influenza, 2020, https://www.medscape.com/

answers/219557-3459/what-is-the-global-incidence-of-influenza ].

Vaccines against enteric infections

Acute gastrointestinal infections and pneumonia are the most

important causes of death in children in the developing world. Cholera is

endemic in South East Asia and in parts of Africa and regularly causes

major epidemics. Salmonella typhi and related bacteria are major causes

of severe illness, especially in Asia, and non-typhoidal salmonella infection

is an important cause of severe illness in children and HIV-infected adults

in Africa. Vaccines against enteric bacterial infections, including typhoid

29

and cholera, have been available for many years but their use has been

restricted largely to tourists and travellers and they have been little used in

developing countries where they would be of most value. However, as a

result of recent epidemiological studies, there is increasing recognition of

the high burden of disease attributable to bacterial enteric infections and of

the role that more widespread deployment of these vaccines could play in

improving health, especially in Asia.

Diarrheal diseases remain a leading cause of mortality globally.

Recent estimates of the Global Burden Disease study showed that nearly

1.65 million diarrheal diseases deaths occurred in 2016 in all ages

globally, of which 446,000 deaths occurred among children aged under 5

years. More than 85% of diarrheal diseases deaths occurred in South Asia

and sub-Saharan Africa. Rotavirus was the leading cause of diarrheal

diseases deaths, being responsible for 228,000 deaths in all age groups,

followed by Shigella causing 212,000 deaths, Vibrio cholera (107,000

deaths), adenovirus (93,000 deaths), non-typhoidal Salmonella (NTS)

(87,000 deaths), Campylobacter (75,000 deaths), Cryptosporidium (57,000

deaths), and enterotoxigenic Escherichia coli (ETEC) (51,000 deaths).14

There are 2 internationally available oral live-attenuated rotavirus

vaccines (licensed around 13 years ago): Rotarix™ (GSK Biologicals,

Rixensart), and RotaTeq ™ (Merck & Co., Whitehouse, Pennsylvania).

These vaccines showed high efficacy in preventing severe rotavirus

gastroenteritis in clinical trials conducted among infants. as well as

acceptable safety profile. These vaccines have been prequalified by the

World Health Organization (WHO) in 2009; the WHO recommended the

introduction of universal rotavirus immunization globally.14\

Cholera remains a major public health problem, with an estimated

burden of 2.86 million cases and 95,000 deaths in endemic countries in

Asia and Africa. There are three licensed and WHO prequalified cholera

vaccines. The first vaccine is Dukoral that contains the cholera toxin B-

subunit (CTB), the other two vaccines Shanchol and Euvichol-plus showed

good effectiveness and were prequalified by the WHO in 2011 and 2015,

30

respectively. In the past few years, cholera vaccines have been available

for emergencies through a global stockpile funded by GAVI.15

Vaccines against non-infectious diseases. Cancer.

Vaccines can be used to control of cancer—prevention of the

development of a cancerous malignancy or control of a cancer once it has

developed. Chronic infections with the hepatitis B virus (HBV) and high-

risk human papillomaviruses (HPVs) are important risk factors for

hepatocellular carcinoma (HCC) and cervical cancer (CC), respectively.

On a global scale, approximately 2 million new cancer cases are

attributed to infectious agents each year worldwide. There are now

successful vaccines for the HBV), and HPV) are considered major

successes in clinical chemoprevention of cancer. Widespread deployment

of these effective vaccines play now an important role in reducing the

increasing burden of these types of cancer in the developing world. There

are many strains of HPV but, fortunately, only a few appear to play an

important role in the causation of cervical cancer. Currently available HPV

vaccines are likely to be highly effective in preventing this cancer.16,17

Global efforts to develop vaccines for protection against COVID-19

In June 2020 there were more than 160 potential vaccines for

COVID-19 under study, optimistic experts hope that a viable vaccine may

be ready by the end of 2020 or beginning of 2021. This large global effort

to develop vaccines for protection against COVID-19 have at least 10

vaccine candidates, as of early June 2020, entered clinical trials, including

phase II trials (there are 3 clinical trials, I, II and III). The European

Medicines Agency (EMA) has been in discussion with developers of 33

potential SARS-CoV-2 vaccines since May 2, 2020. However, the EMA

expects that it may take at least one year before a vaccine is approved

and available for widespread use in the EU/EEA

31

[European Centre for Disease Prevention and Control 11.6.2020,

https://www.ecdc.europa.eu/en/covid-19/latest-evidence/vaccines-and-

treatment ].

On June 19, 2020 the weekly journal of the American Chemical

Society, Chemical and Engineering News published an interesting article:

Crose R. COVID-19 vaccines and antibodies advance even faster than

expected. With large vaccine trials planned and monoclonal antibody trials

underway, efficacy data could come this fall or winter. C&E NEWS, JUNE

19, 2020 , VOLUME 98, (ISSUE 24).

― ……Early in the COVID-19 pandemic, infectious disease experts said

that developing a vaccine for the virus would take at least 12–18 months.

Now, in their continued blitzkrieg against SARS-CoV-2, the novel

coronavirus that causes COVID-19, several drug companies are keeping

pace with their ambitious timelines, and some are moving even faster than

they initially predicted.

―…Three companies with funding from the US government—

AstraZeneca, Johnson & Johnson, and Moderna—are on track to

distribute the first commercial batches of their experimental vaccines in

late 2020 or early 2021. Those firms are top players in Operation Warp

Speed, the US plan to have 300 million doses of a safe and effective

COVID-19 vaccine by January 2021. Separately, several groups began

clinical trials in June of monoclonal antibodies designed to target and

neutralize SARS-CoV-2. Although many older drugs are being repurposed

as potential COVID-19 therapies, the antibody trials helmed by Eli Lilly

and Company, Regeneron Pharmaceuticals, and Singapore-based

Tychan are the first to test drugs created specifically for treating COVID-

19…‖

―…..The pandemic is pushing drug companies to develop and test their

wares at unparalleled speeds. ―There is no reason you couldn’t speed up

drug development if you really focused on it, and that’s what the pandemic

has brought,‖ says Lisa Kennedy, CEO of the life sciences consulting firm

Innopiphany.

32

Figure 18. Regeneron's preclinical manufacturing laboratory, where selected antibodies for preclinical and toxicology studies will be made in stainless steel bioreactors. (Board of Directors: Schleifer LS, Yancopoulos GD).

―…..Never have so many groups been working on vaccines and

treatments for the same disease, says Esther Krofah, executive director of

FasterCures, a medical research advocacy division of the Milken Institute.

―We have to be cautiously optimistic,‖ Krofah says. ―Clinical trials are

notorious for not going well.‖

―…Large trials this summer and fall could provide the first evidence

that some of the experimental COVID-19 vaccines are working.

AstraZeneca, which is developing an adenoviral vector vaccine designed

at the University of Oxford (Jenner Institute, https://www.jenner.ac.uk/), is

recruiting 10,000 people in the UK, 30,000 people in the US, and

potentially 2,000 people in Brazil for its Phase III study to determine if the

vaccine is effective. If the trial is successful, AstraZeneca says, it could

start distributing the vaccine as early as September in the UK and October

in the US…‖

“…Moderna plans to begin a 30,000-person Phase III study of its

messenger RNA (mRNA) vaccine in July. The firm is working with the

contract manufacturer Lonza to produce 500 million doses or more per

year. Johnson & Johnson (J&J), which like AstraZeneca is developing

33

an adenoviral vector vaccine, says it will begin its first clinical trial in the

second half of July—two months earlier than anticipated. The trial will test

the vaccine in 1,045 healthy volunteers in the US and Belgium. J&J is also

trying to move faster on planning for its larger trials…‖

―…The Chinese companies Sinovac and China National

Pharmaceutical Group—also known as Sinopharm—are prepping for

Phase III studies of their vaccines outside China. Both firms are

developing vaccines made from chemically inactivated SARS-CoV-2. They

say people receiving their vaccines in Phase II studies developed

neutralizing antibodies to the virus, but the data have not been published.

Krofah says monoclonal antibodies could ―be a bridge to a vaccine‖ before

vaccines are widely available…‖

“…Eli Lilly was the first company to begin clinical trials of

monoclonal antibodies, discovered by the Canadian company AbCellera

Biologics and the Chinese firm Shanghai Junshi Biosciences. It took only

about 90 days from the start of AbCellera’s discovery program to the first

injection of the antibody in a clinical trial. ―Typically, that process could

take between 1 1/2 to 2 years minimum, so doing it in 3 months is

extraordinary,‖ says Janice Reichert, executive director of The Antibody

Society, a trade organization. Others are also moving fast. Regeneron has

begun two clinical trials of an experimental therapy that includes two

monoclonal antibodies that target SARS-CoV-2. Tychan says it has begun

clinical trials of its antibody in China..‖

―…By Reichert’s estimation, there could be upward of 20 SARS-

CoV-2 antibody programs in clinical studies by the end of the year, and it

should not take long to determine if these drugs are effective. Lilly says it

could have data by the end of the summer. ―The readout is pretty quick

with COVID-19,‖ Reichert says. ―You either get better or you don’t.‖ If the

clinical trials are successful, vaccine and antibody developers alike have

suggested that their products could be available to certain groups through

the US Food and Drug Administration’s emergency use authorization

(EUA), rather than a formal approval. The FDA announced an EUA for the

34

antiviral drug Remdesivir in May, three weeks before data from clinical

trials were published…‖

―…Vaccines for COVID-19 are likely to first be available through

EUA, Krofah says, and she stresses the need for companies to publish

data quickly in such a situation. ―It is very important that all of the safety

and efficacy data is shared and available publicly so that the public has

confidence that this is not being hurried…‖.

Conclusions

Vaccination has made an enormous contribution to global health.

Global coverage of vaccination against many infectious diseases of

childhood has been enhanced dramatically since the creation of WHO's

Expanded Programme of Immunization (EPI) in 1974 and of the Global

Alliance for Vaccination and Immunization (GAVI) in 2000. Polio has

almost been eradicated and success in controlling measles makes this

infection another potential target for eradication. Despite these successes,

approximately 6.6 million children still die each year and about a half of

these deaths are caused by infections, including pneumonia and

diarrhoea, which could be prevented by vaccination. Development of

vaccines against more complex infections, such as malaria, tuberculosis

and HIV, has been challenging and achievements so far have been

modest. But in the longer term, widespread campaigns for vaccines are

likely to be used to prevent or modulate the course of some non-infectious

diseases. Progress has already been made with therapeutic cancer

vaccines and future potential targets for new vaccines include addiction,

diabetes, hypertension and Alzheimer's disease.

It is indisputable that vaccines and immunization has made the

greatest contribution to global health, second only to the introduction of

clean water and sanitation. From the end of the 19th century onwards

vaccines contributed to the decline in child mortality from infectious

diseases and has made an enormous contribution to human health,

especially in the developing world.

35

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